Design of a Wideband Right-Angle CPWG-to-Waveguide Transition for <i>Ku</i>-Band Applications

This letter presents a novel wideband planar coplanar waveguide with ground (CPWG)-to-rectangular waveguide (RWG) transition designed for Ku-band applications. The architecture employs a stacked patch structure integrated with shorting via walls, which are pivotal for mode conversion. The design incorporates dual matching techniques—mode and impedance matching—to extend the bandwidth. Specifically, the cross-slot magnetic currents induce an E-field that aligns with the TE10 mode of the waveguide, while the matching elements effectively suppress the undesirable higher order TM11 mode resonance. The transition operates over a bandwidth of 10.5–15.8 GHz (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta f =39.7$ </tex-math></inline-formula>%) with corresponding total insertion losses (ILs) maintained below 1.33 dB. The transition demonstrates an IL of up to 0.7 dB within its operational bandwidth.